1. Field of the Invention
The present invention relates to a method for producing fucoxanthin. In particular, the present invention relates to a method for extracting fucoxanthin from botanic material.
2. Description of the Related Art
Fucoxanthin is red brown, which is one of important carotenoids, and has very strong antioxidation effect. Its formula is C42H58O6 and it has the following structural formula:

Fucoxanthin, as a kind of carotenoids, is a natural active substance and has high physiological activity. It has very high potential value of development and utilization, as it can regulate blood glucose of the diabetic better, kill lots of cancer (breast cancer, colorectal cancer, prostate cancer and so on) cells, and have very strong antioxidation effect.
However, the content of fucoxanthin in raw material is very low, only 50-100 ppm. Furthermore, this product is powerful antioxidant, thereby it is easily decomposed during producing process. Therefore, its production is very difficult. In addition, the raw material is seaweeds which absorb heave metals and arsenic salt in the sea, thus the obtained extract may contain a large amount of heave metals and arsenic salt during the extraction of fucoxanthin. Therefore, it is always an important problem of the development for fucoxanthin how to reduce the content of heavy metal and arsenic salt during the production of fucoxanthin.
Chinese Patent No. CN1706836 discloses a method for separating fucoxanthin from seaweeds. The detailed operation steps are: washing fresh seaweeds or frozen seaweeds that are thawed at the room temperature with distilled water; then removing water from the surface thereof, and then lixiviating seaweeds by using dimethyl sulfoxide in dark for 15-60 minutes, wherein the amount of dimethyl sulfoxide is 2 ml-6 ml per gram of seaweed. As dimethyl sulfoxide is used as the extraction solvent in this method, the harmful organic solvent is used. Moreover, the boiling point of the solvent is relative high and it is very difficult to remove the organic solvent by conventional operation, therefore the harmful organic solvent will remain in the extract product, so that the product safety is reduced greatly. Furthermore, dimethyl sulfoxide solvent costs much, the production cost is thus increased, and thereby it is not suitable for industrial production. Meanwhile, in the product obtained by the above method, the content of heavy metal and the arsenic salt does thus not accord with the present standard for food additives, which limits the application of this method.